Actor Ben Stiller, left, and actress Kristen Wiig, right, attend a screening of "The Secret Life of Walter Mitty" on Wednesday, Dec. 18, 2013, in New York. AP Photo.

The crowded field of movie openings Wednesday includes Martin Scorsese's "The Wolf of Wall Street," Ben Stiller's "The Secret Life of Walter Mitty," the Robert De Niro and Sylvester Stallone comedy "Grudge Match," the Justin Bieber documentary "Justin Bieber's Believe" and Keanu Reeves' "47 Ronin."

"It is going to be one heck of a crowded Christmas Day at the movie theater," said Paul Dergarabedian, senior media analyst for box-office tracker Rentrak. "This is setting up to be perhaps one of the biggest Christmas Days ever."

"The Secret Life of Walter Mitty," starring and directed by Ben Stiller, is expected to be a big hit. It's adapted from James Thurber's classic short story that first appeared in The New Yorker in 1939. Since then, Walter Mitty (a mild-mannered man who enlivens a mundane day with a series of fantasies) has been synonymous with daydreaming and flights of imagination.